how thick should it be stock port, then street port?

 

stock or street you should use 1/8" wall thickness. tubing. Yup! It's pretty darn thick. You can buy it in 4 foot lengths from Mazdatrix. My local muffler shop guy was shocked to see how thick it was but he was able to bend it to shape no problem. He really enjoyed working with such substantial and quality parts.

 

muffler shops that install rollbars use rollbar tubing. 1/8" wall thickness of course.

 

ok, and what about the diameter of the hole? 2" right?

 

Go through the Racing Beat site where they cover headers and write down the various sizes and primary lengths they recommend. Think hard and carefully on exactly how you plan to use the car that the "header" is going on to and then go from there....

 

.10-.12". for HEADERS, the rear section can be ordinary exhaust tubing.

 

can I butt in and ask a silly, silly question?

Racing Beat recommend 1/8" tubing, a 1 7/8" id and they use a 2" od pipe.

Did I skip a chapter in school or is their maths wrong?

Mark

 

D'oh!!

Maybe 2" tubing isn't really 2" tubing in the exhaust world...just guessing

 

1/8 + 1 7/8 = 2

What part don't I understand?

 

There's two walls.... 1 7/8 + 2 * 1/8 != 2

 

that should be = 2 1/8"

I would guess that racing beat uses 2" 16 SWG tubing for the headers as that ties in nicely with the ID and OD sizes

 

good, so it wasn't just me.

It never occured to me until I sat down one day to plan a set of custom extractors for the 13b bp going into my little Mazda 1300.

I think just asking for 1 7/8" id pipe with thick wall is the easiest. When I ended up getting my car with new extractors back I found they had made it from 2 1/8" id (instead of 2 1/8" od) pipe. And the outside was a whopping 2 3/8 or so! It was hell loud.

Lesson for the day: write down what you want.

Mark

 

i hate fractions....

metric all the way!

 

~T.J.